Glass sleeve internal polishing

ABSTRACT

A magnetic polisher and a method of use magnetic polisher for polishing a glass sleeve are described. The magnetic polisher may comprise at least one rotatable driver and at least one rotatable polishing tool. The at least one rotatable driver may comprise driver magnetic material. The at least one rotatable polishing tool may comprise tool magnetic material and a first polishing surface. At least one of the driver magnetic material and the tool magnetic material may be a magnet. The driver and polishing tool may be configured to be magnetically coupled with a workpiece. The workpiece may have at least a first internal surface to be polished. The workpiece may be located between the first polishing surface and the driver. The rotation of the driver about an axis may cause rotation of the first polishing surface against the first internal surface.

This application claims the benefit of priority under 35 U.S.C. §119 ofU.S. Provisional Application Ser. No. 62/109857 filed on Jan. 30, 2015the content of which is relied upon and incorporated herein by referencein its entirety.

FIELD

The disclosure relates to systems and methods for polishing internalsurfaces of a hollow structure, and more particularly to a system, suchas a magnetic polisher, for polishing an internal surface of a glasssleeve, and methods for polishing a glass sleeve to produce athree-dimensional formed glass cover for a handheld smart phone or otherconsumer electronic device. The glass cover optionally may besleeve-shaped.

SUMMARY

The present disclosure relates, in various embodiments, generally to amagnetic polisher for polishing internal surface of glass sleeve. Themagnetic polisher may comprise at least one rotatable driver and atleast one rotatable polishing tool. The at least one rotatable drivermay comprise driver magnetic material. The at least one rotatablepolishing tool may comprise tool magnetic material and a first polishingsurface. At least one of the driver magnetic material and the toolmagnetic material may be a magnet. The driver and polishing tool may beconfigured to be magnetically coupled with a workpiece. The workpiecemay have at least a first internal surface to be polished. The workpiecemay be located between the first polishing surface and the driver. Therotation of the driver about an axis may cause rotation of the firstpolishing surface against the first internal surface.

The present disclosure relates, in various embodiments, to a method forpolishing a glass sleeve with a flattened portion. The method may beuseful in manufacturing a sleeve-like structure. The method is carriedout by providing a glass sleeve. The glass sleeve may have at least onesubstantially flat internal surface extending along a longitudinal axisand an internal opening extending along the longitudinal axis enclosinga space. A rotatable polishing tool may be introduced to polish theglass sleeve. The rotatable polishing tool may include a magneticmaterial and a first polishing surface which may be brought into thespace within the glass sleeve. The first polishing surface may bebrought into contact with the substantially flat internal surface. Arotatable driver may be introduced. The rotatable driver may include amagnetic material outside the glass sleeve. The tool magnetic materialmay be a magnet so that the driver may magnetically couple with thepolishing tool. The driver may be rotated, causing the polishing tool torotate.

Additional features and advantages of the present disclosure will be setforth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the embodiments described herein, including thedetailed description which follows, the claims, as well as the appendeddrawings.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The following is a description of the figures in the accompanyingdrawings. The figures are not necessarily to scale, and certain featuresand certain views of the figures may be shown exaggerated in scale or inschematic in the interest of clarity or conciseness.

FIG. 1 is a schematic side view of a magnetic polisher in use accordingto an embodiment;

FIG. 2 is a schematic side view of a magnetic polisher in use accordingto another embodiment;

FIG. 3 is a top view of a rotatable polishing tool in use according tothe embodiment of FIG. 2;

FIG. 4 is a perspective view of a polishing pad usable, for example, inthe embodiments of any Figure;

FIG. 5 is a schematic side view of a magnetic polisher usable, forexample, in the embodiments of any Figure;

FIG. 6 is a schematic side view of another type of magnetic polisherusable, for example, in the embodiments of FIGS. 1-4 and 7; and

FIG. 7 is a flow chart illustrating a method for polishing a glasssleeve according to one embodiment.

The following reference characters are used in this specification:

100 Magnetic polisher 102 Axis 110 Rotatable driver 120 Rotatablepolishing tool 122 Polishing surface 130 workpiece 132 First internalsurface 140 Driving motor 140 Variable spacer 150 Translation stage 160Magnet for driver 170 Magnet for polishing tool 180 Polishing pad 210Shaft 410 radial slots 500 Driving pad 510 Driver polishing surface 520External surface 600 Internal spring 610 Second polishing surface 620second internal surface 630 Second non-magnetic polishing pad 640Polishing paper 700 Method for polishing a glass sleeve 710 First stepof the method 720 Second step of the method 730 Third step of the method740 Fourth step of the method 750 Fifth step of the method

The foregoing summary, as well as the following detailed description ofcertain inventive techniques, will be better understood when read inconjunction with the figures. It should be understood that the claimsare not limited to the arrangements and instrumentalities shown in thefigures. Furthermore, the appearance shown in the figures is one of manyornamental appearances that can be employed to achieve the statedfunctions of the apparatus.

DETAILED DESCRIPTION

The present disclosure can be understood more readily by reference tothe following detailed description, drawings, examples, and claims, andthe previous and following description. However, before the presentcompositions, articles, devices, and methods are disclosed anddescribed, it is to be understood that this disclosure is not limited tothe specific compositions, articles, devices, and methods disclosedunless otherwise specified, as such can, of course, vary. It is also tobe understood that the terminology used herein is for the purpose ofdescribing particular aspects only and is not intended to be limiting.

The following description of the disclosure is provided as an enablingteaching of the disclosure in its currently known embodiments. To thisend, those skilled in the relevant art will recognize and appreciatethat many changes can be made to the various aspects of the disclosuredescribed herein, while still obtaining the beneficial results of thepresent disclosure. It will also be apparent that some of the desiredbenefits of the present disclosure can be obtained by selecting some ofthe features of the present disclosure without utilizing other features.Accordingly, those who work in the art will recognize that manymodifications and adaptations to the present disclosure are possible andcan even be desirable in certain circumstances and are a part of thepresent disclosure. Thus, the following description is provided asillustrative of the principles of the present disclosure and not inlimitation thereof.

Disclosed are materials, compounds, compositions, and components thatcan be used for, can be used in conjunction with, can be used inpreparation for, or are embodiments of the disclosed method andcompositions. These and other materials are disclosed herein, and it isunderstood that when combinations, subsets, interactions, groups, etc.of these materials are disclosed that while specific reference of eachvarious individual and collective combinations and permutation of thesecompounds may not be explicitly disclosed, each is specificallycontemplated and described herein.

Reference will now be made in detail to the present preferredembodiment(s), examples of which are illustrated in the accompanyingdrawings. The use of a particular reference character in the respectiveviews indicates the same or like parts.

As noted above, broadly, this disclosure teaches a magnetic polisher anda process to polish an internal surface of a glass sleeve by using amagnetic polisher. The present disclosure involves a process forgrinding and polishing the internal surface of a glass sleeve whichpresents a narrow open frontal area (6-8×60-70 mm) and a deep cavity(120 -140 mm), preventing use of conventional finishing techniques. Theglass surface quality, potentially affected by tube reforming processes,may need to be compatible with display applications, optical clarity,non-local deformations or local surface defects, such as pits,scratches, or dimples. These defects may typically have roughness higherthan 0.2 nm, for example. The current disclosure may involve a magneticcoupling between one or more inner rotatable polishing tools put inrotation by an external rotating motor. It may also involve a stage orother translation mechanism in order to manage the polishing of agenerally rectangular surface with a substantially round tool. Themagnetic coupling may be insured by a North or South pole orientation ofmagnets.

The disclosure may present many advantages, such as internal surfacefinishing of non-accessible flat glass cavity, thin polishing tool beingable to enter a fragile narrow glass cavity; magnetic coupling betweenthe polishing tool and an external rotating motor, flexible andcompliant polishing tool being able to follow a generally flat surfacethat could involve a very large radius of curvature (such as severalmeters). The advantages may further include combined translation motionin order to be able to generate a flat polished surface, use ofdifferent grain size grinding and polishing mediums that may be coatedpapers, fabric or polyurethane pads with free abrasive, possible doubleside polishing, internal and external at the same time, possible doubleinternal side polishing, cost effective technique that may be applied tofinished sleeve enclosure or long sleeve preforms before cutting andedge finishing, control of the grinding and polishing force by variationof the power/density of magnetic elements and/or of the magnetic gap inbetween the driving and the grinding parts.

As used herein, the term “sleeve” describes a three-dimensional, tubularglass article having a non-circular cross section and an aspect ratiogreater than 1. The aspect ratio is the ratio of the largest andsmallest diameters of the cross section of the tubing or sleeve. Theaspect ratio has a minimum value of 1 by definition for a round oraxisymmetric tube. The aspect ratio has a value larger than 1 for aflattened sleeve. Optionally in any embodiment, aspect ratios from about1.5 to about 50, optionally from about 3 to about 39, optionally fromabout 5 to about 25, optionally from about 5 to about 15, optionallyfrom about 7 to about 11, optionally from about 18 to about 28, arecontemplated.

While most of the embodiments herein are used particularly inapplication to sleeve glass enclosures, it is contemplated that the samemethod could be applied more widely, for example with an additional stepof cutting the tubes in half or severing optically flat portions toprovide for a 3D shaped cover glass, touch screen, or other part.

As shown in the Figures, the magnetic polisher 100 may include at leastone rotatable driver 110 and at least one rotatable polishing tool 120.The at least one rotatable driver 110 may include driver magneticmaterial, such as a magnet 160. The at least one rotatable polishingtool 120 may include tool magnetic material, such as a magnet 170, and afirst polishing surface 122. In one embodiment, the at least one magnet160 or 170 may include a permanent magnet, such as neodymium magnet,samarium-cobalt or an alloy of neodymium, neodymium-iron-boron (NIB)magnet, for example. The at least one of the driver magnetic materialand the tool magnetic material may comprise a magnetic neodymium alloy,such as neodymium-iron-boron magnet. In another embodiment, the magnet160 for driver magnetic material may be electromagnet.

Optionally in any embodiment, the rotatable driver 110 and the polishingtool 120 may be configured to be magnetically coupled with a workpiece130, such as a glass sleeve. The rotatable driver 110 may be connectedto a driving motor 140. The rotatable driver 110 may be operated atvarious speeds ranging from 200 to 800 rpm, for example. The workpiece130 may have at least a first internal surface 132 to be polished. Theworkpiece 130 may be located between the first polishing surface 122 andthe driver 110 so that rotation of the driver 110 about an axis 102 maycause rotation of the first polishing surface 122 against the firstinternal surface 132. The first polishing surface 122 may be defined bya non-magnetic polishing pad 180. The non-magnetic polishing pad 180 maybe used in order to prevent any impact on the magnetic coupling betweenthe polishing pad 180 and the rotatable driver 110. A magnetic polishingpad 180 may alternatively be used, if desired.

The magnetic polisher 100 may further include a variable spacer 140. Thevariable spacer 140 may be configured to adjust and maintain the axialdistance between the rotatable driver 110 and the rotatable polishingtool 120, while the first internal surface 132 is located between thefirst polishing surface 122 and the driver 110 to provide the desirednormal force between the first polishing surface 122 and the firstinternal surface 132. The variable spacer 140 may allow a fine tuning ofthe grinding or polishing force. The variable spacer may vary from 2 to10 mm for 50 N to 5 N corresponding forces, for example. In anotherembodiment, the variable spacer may be less than 2 mm or more than 10 mmdepending on the workpiece 130. There may be many advantages of using avariable spacer 140. For example, as one of the advantages, therotatable driver 110 may be configured to remain out of contact with theworkpiece 130, such as a glass sleeve, when the rotatable driver 110 andthe polishing tool 120 are magnetically coupled and the first polishingsurface 122 is rotating against the first internal surface 132.

The magnetic polisher 100 may further include a translation stage 150upon which either the workpiece 130 or the rotatable driver 110 may bemounted. The translation stage may allow the workpiece 130 to be movedrelative to the magnetic polisher 100 generally perpendicular to therotation axis 102. As shown in FIG. 2, for example, the translationstage 150, such as a translation belt, may be connected to a shaft 210of the motor so that one motor 140 may control several, such as four,rotatable drivers 110. The rotatable drivers 110 may in turn controlseveral, such as four, polishing tools 120 to have individual tool 120overlapping for uniform polishing (as shown in FIG. 3). In this way, theinternal surface polishing may be operated on a long sample, such asexceeding one meter, on a multi-head polishing set-up. The translationbelt may form a rotating system.

As shown in FIG. 3, in one embodiment, the workpiece 130, such as aglass sleeve, to be internally polished may sit on the translation stage150, such as a translation belt, being also motorized in order to insurethe polishing of the whole internal surface. The translating support maymove on both directions covering the whole surface at a rate of 2 to 10cycles per minute, for example. In another embodiment, the translationstage 150 may be used to translate the rotatable driver 110 relative tothe workpiece 130.

The polishing pad 180 may be equipped with one or more magnets. Forexample, still in FIG. 3, the polishing pad 180 may be equipped withfour magnets 170, for example. The four magnets 170 may be arrangedspreading out as a cross. In another embodiment, in FIG. 4, thepolishing pad 180 may have 6 magnets 170, which equally spread close tothe periphery of a polymer disk. As an example, the polymer disk canhave a diameter of about 60 mm. The magnet 170 may have 12 mm diameterand 3 mm high iron Neodymium magnet. The magnet 170 may fit into about 6radial slots 410. The radial slots may allow some compliancy in additionto polymer intrinsic stiffness that may be adjusted from totally rigid(aluminum), mid stiff (polyvinyl carbonate, Delrin, polypropylene) tosoft (polyurethane, silicone), for example. The polishing pad 180 may be4 mm thick for a 6 mm thick radial slot, leaving enough room forgrinding or polishing paper or polyurethane layer usually stuck to it.

As shown in FIG. 5, the rotatable driver 110 may comprise a driverpolishing surface 510 configured to contact an external surface 520 ofthe workpiece 130 to be polished during rotation of the first polishingsurface 122 against the first internal surface 132. In one embodiment,the driver polishing surface 510 may be defined by a non-magneticpolishing driving pad 500. The magnetic coupling may be insured bynon-magnetic driving pad 500 involving the corresponding set of magnets160. These magnets 160 may be advantageously thicker, in order toprovide potentially higher coupling forces, or/and larger gap in betweenpads. In one embodiment, the driving magnets 160 may have about 12 mmdiameter, about 6 mm high, for example. Magnets may be secured onpolymer pads with bi-component structural adhesives non-sensitive tomoisture. Optionally in all embodiments, all magnets on polishing anddriving pads may be oriented top north by convention.

Still in FIG. 5, the polisher 100, while shown approximately as wide asthe glass sleeve, may be substantially smaller than the glass sleeve.The polisher 100 may be moved about the internal or external surfaces ofthe sleeve in a random or ordered manner in order to deliver uniformsurface finishing, for example.

The polishing tool may further include a second polishing surface 610axially separated from the first polishing surface 122, as shown in FIG.6. The second polishing surface 610 may be configured to contact asecond internal surface 620 of the workpiece 130 to be polished duringrotation of the first polishing surface 122 against the first internalsurface 132. The second polishing surface 610 may be defined by a secondnon-magnetic polishing pad 630. The first and second non-magneticpolishing pad 180 and 620 may be covered by a polishing paper 640. Apolishing tool 100 may further include an expander urging the first andsecond polishing pads apart, such as an internal spring 600, acompressive polymer layer or an expandable polymer that functions as aspring, a pneumatic or hydraulic cylinder and piston, an expandablepneumatic or hydraulic diaphragm or bladder, a telescoping lead screw ina threaded sleeve, a magnetic repulsion provided by magnets with facingnorth or facing south poles, or any other suitable expansion device, tomaintain contact between the first and second polishing surfaces 122 and620 and the first and second internal surfaces 132 and 620. The expandermay help expand the double side polishing pads to polish both internalsurfaces of the workpiece.

Optionally in any embodiment, a polishing pad, as shown in FIGS. 5 and6, may have rounded edges that contact a part or all of the rounded areaof the sleeve. Optionally, the rounded edges may mirror the shape ofpart or all of the rounded area of the sleeve. For example, thepolishing pad may have permanently rounded edges. For another example,the rounded edges of the polishing pad may be composed of a sufficientlyflexible material to conform to a part or all of the rounded area of thesleeve during polishing.

In another embodiment, a method 700 for polishing a glass sleeve may becarried out as follows, for example. Step 710 is providing a glasssleeve having at least one substantially flat internal surface extendingalong a longitudinal axis and an internal opening extending along thelongitudinal axis, enclosing a space. Step 720 is introducing arotatable polishing tool comprising a magnetic material, such as amagnetic alloy of neodymium, and a first polishing surface into thespace. Step 730 is bringing the first polishing surface into contactwith the substantially flat internal surface. Step 740 is introducing arotatable driver comprising a magnetic material to the exterior of theglass sleeve, wherein at least one of the driver magnetic material andthe tool magnetic material is a magnet, such as a neodymium magnet, suchthat the driver magnetically couples with the polishing tool. Step 750is rotating the driver, causing the polishing tool to rotate. Optionallyin any embodiment, the polishing tool further comprises a secondpolishing surface axially separated from the first polishing surface.The method further may comprise bringing the second polishing surfaceinto contact with a second substantially flat internal surface of theglass sleeve. Optionally in any embodiment, the driver may furthercomprise a driver polishing surface. The method 700 may further comprisebringing the driver polishing surface into contact with an externalsurface of the glass sleeve.

The method 700 may be further carried out by biasing the first andsecond polishing surfaces axially apart against the first and secondsubstantially flat internal surfaces and mounting at least one of theglass sleeve and the rotatable driver upon a translation stage. Thetranslation stage allows at least one of the workpiece and the polishingtool to be moved generally perpendicular to the axis of rotation,relative to the other of the workpiece and the polishing tool.

In operation, a glass sleeve may be mounted inside a holder, such as aV-shaped holder, and the following grinding sequence can be used, forexample.

Grinding paper (600 mesh) may be put on a grinding pad. The glass sleevemay be ground at about 200 rpm, 4×45 mm amplitude during a 2-minute run.The glass sleeve then may be rinsed with water.

Grinding paper (1200 mesh) may then be put on the grinding pad. Theglass sleeve may be ground at 200 rpm, at 4×45 mm amplitude during a4-minute run. The glass sleeve then may be rinsed with water.

Polishing paper having a 9-micron grid may then be put on a polishingpad. The glass sleeve may be polished at 200 rpm, at 4×45 mm amplitudeduring an 8-minute run. The glass sleeve may be rinsed with water afterthat.

Polishing paper having a 3-micron grid may be put on the polishing pad.The glass sleeve may be polished at 200 rpm, 4×45 mm amplitude during an8-minute run. The glass sleeve may be rinsed with water after that.

A polyurethane layer may be put on a finishing pad. The glass sleeve maybe polished at 200 rpm at 4×45 mm amplitude during an 8-minute run. Theglass sleeve may be rinsed with water after that. After the grinding andpolishing have been completed, the internal surface may presentflattened topography.

While the invention has been described with respect to a limited numberof embodiments, those skilled in the art, having benefit of thisdisclosure, will appreciate that other embodiments can be devised whichdo not depart from the scope of the invention as disclosed herein.Accordingly, the scope of the invention should be limited only by theattached claims.

1. A magnetic polisher comprising: a. at least one rotatable drivercomprising driver magnetic material; b. at least one rotatable polishingtool comprising tool magnetic material and a first polishing surface;wherein at least one of the driver magnetic material and the toolmagnetic material is a magnet, and the driver and polishing tool areconfigured to be magnetically coupled with a workpiece having at least afirst internal surface to be polished located between the firstpolishing surface and the driver, such that rotation of the driver aboutan axis causes rotation of the first polishing surface against the firstinternal surface.
 2. The magnetic polisher of claim 1, wherein at leastone magnet comprises a permanent magnet.
 3. The magnetic polisher ofclaim 1, at least one of the driver magnetic material and the toolmagnetic material comprises a magnetic neodymium alloy.
 4. The magneticpolisher of claim 1, wherein the first polishing surface is defined by anon-magnetic polishing pad.
 5. The magnetic polisher of claim 1, whereinthe polishing tool further comprises a second polishing surface axiallyseparated from the first polishing surface, wherein the second polishingsurface is configured to contact a second internal surface of theworkpiece to be polished during rotation of the first polishing surfaceagainst the first internal surface.
 6. The magnetic polisher of claim 5,wherein the second polishing surface is defined by a non-magneticpolishing pad.
 7. The magnetic polisher of claim 5, wherein thepolishing tool further comprises an internal spring to maintain contactbetween the first and second polishing surfaces and the first and secondinternal surfaces.
 8. The magnetic polisher of claim 1, wherein thedriver further comprises a driver polishing surface configured tocontact an external surface of the workpiece to be polished duringrotation of the first polishing surface against the first internalsurface.
 9. The magnetic polisher of claim 8, wherein the driverpolishing surface is defined by a non-magnetic polishing pad.
 10. Themagnetic polisher of claim 1, further comprising a translation stageupon which either the workpiece or the driver is mounted, wherein thetranslation stage allows the workpiece to be moved relative to themagnetic polisher generally perpendicular to the rotation axis.
 11. Themagnetic polisher of claim 1, further comprising a variable spacerconfigured to adjust and maintain the axial distance between therotatable driver and the rotatable polishing tool, while the firstinternal surface is located between the first polishing surface and thedriver, to provide the desired normal force between the first polishingsurface and the first internal surface.
 12. The magnetic polisher ofclaim 1, in which the driver is configured to remain out of contact withthe workpiece when the driver and polishing tool are magneticallycoupled and the first polishing surface is rotating against the firstinternal surface.
 13. A method for polishing a glass sleeve comprising:a. providing a glass sleeve, the glass sleeve having at least onesubstantially flat internal surface extending along a longitudinal axisand an internal opening extending along the longitudinal axis enclosinga space; b. introducing a rotatable polishing tool comprising a magneticmaterial and a first polishing surface into the space; c. bringing thefirst polishing surface into contact with the substantially flatinternal surface; d. introducing a rotatable driver comprising amagnetic material to the exterior of the glass sleeve, wherein at leastone of the driver magnetic material and the tool magnetic material is amagnet, such that the driver magnetically couples with the polishingtool; and e. rotating the driver, causing the polishing tool to rotate.14. The method for polishing of claim 13, wherein the magnet is aneodymium magnet.
 15. The method for polishing of claim 13, wherein themagnetic material comprises a magnetic alloy of neodymium.
 16. Themethod for polishing of claim 13, wherein the polishing tool furthercomprises a second polishing surface axially separated from the firstpolishing surface, the method further comprising bringing the secondpolishing surface into contact with a second substantially flat internalsurface of the glass sleeve.
 17. The method for polishing of claim 16,further comprising biasing the first and second polishing surfacesaxially apart against the first and second substantially flat internalsurfaces.
 18. The method for polishing of claim 1, wherein the driverfurther comprises a driver polishing surface, the method furthercomprising bringing the driver polishing surface into contact with anexternal surface of the glass sleeve.
 19. The method for polishing ofclaim 13, further comprising mounting at least one of the glass sleeveand the rotatable driver upon a translation stage, wherein thetranslation stage allows at least one of the workpiece and the polishingtool to be moved generally perpendicular to the axis of rotation,relative to the other of the workpiece and the polishing tool.